Self-wetting foam product and method of making same

ABSTRACT

SOLID SELF-WETTING FLORAL FOAM CONTAINING AMMONIUM NEUTRALIZED RESIDUE OF MINERAL ACID CATALYST WITH INTERCONNECTED CELLS HAVING CONNATELY AND GENERALLY UNIFORMLY DISTRIBUTED UNREACTED ANIONIC SULFONATE WETTING AGENT CONTENT OF 11/2 TO 3 WEIGHT PERCENT ISOLATED BY NONIONIC WETTING AGENT FROM THE CATALYST RESIDUE AND THE PHENOLIC OF THE FOAM, MANUFACTURED BY MIXING PHENOLIC RESIN AND CARBON BLACK WITH NONIONIC WETTING AGENT, MIXING IN THE SULFONATE, ADDING AND MIXING MORE NONIONIC WETTING AGENT, FOAMING THE MIXTURE WITH MINERAL ACID, RECOVERING THE RESULTING SOLID FOAM PRODUCT, AND NEUTRALIZING RESIDUAL ACID WITH AMMONIA TO TURM THE FOAM FROM BLACK TO GREEN. THE NONIONIC WETTING AGENT AND SULFONATE WETTING AGENT ADDITIONS CAN BE SPLIT INTO TWO ADDITIONS SO THAT A PORTION OF THE NONIONIC WETTING AGENT IS ADDED FOLLOWED BY A PORTION OF THE SULFONATE, THE REMAINDER OF THE NONIONIC AND THEM THE REMAINDER OF THE SULFONATE. THE ACHIEVESR FASTER WETTING AND MAXIMUM WATER ABSORPTION IN THE FOAM PRODUCT.

Oct. 10, 1972 A. M. PALOMBO 3,691,457

SELF-WETTING FOAM PRODUCT AND METHOD OF MAKING SAME Filed March 17 1971vUnited States Patent O" Patented Oct. 10, 1972 3,697,457 SELF-Wm FOAMPRODUCE AND US. CL 26th-2.5 F 22 Claims ABS'IRACI' 0F THE DISCLOSURESolid self-wetting oral foam containing ammonium neutralized residue ofmineral acid catalyst with interconnected cells having connately andgenerally uniformly distributed unreacted` anionic sulfonate wettingagent content of 1% to 3 weight percent isolated by nonionlc wettingagent from the catalyst residue and the phenolic of the foam,manufactured by mixing phenolic resin and carbon black. with nonionicwetting agent, mixing in the sulfonnte, adding and mixing more nonionicwetting agent, foaming the 'mixture with mineral acid, recoverlng theresulting solid foam product, and neutralizing residual acid withammonia to turn the foam from black to green.

The nonionic wetting agent and sulfonate wetting agent additions can besplit into two additions so that a portion of the noniouic wetting agentis added followed by a portion of the sulfonate, the remainder of thenonionic and then. the remainder of the sulfonate. This achieves fasterwetting and maximum water absorption in the foam product.

l CROSS REFERENCE TO REIATED APPLICATION This application is acontinuation-impart of my application Ser. No. 652,229, entitled FloralFoam and Method of Making Same," tiled July 10, 1967, now abandoned.

BACKGROUND OF THE IINVENTION (l) Field of the invention This inventionrelates to self-wetting, phenolic foams and to a method of making suchfoams. More particular- Iy, the invention relates to self-wettingphenolic foam masses containing an effective surface active wettingagent rendering the foam capable of rapidly absorbing liquids.

(2) Description of the prior art `My U.S. Pat. No. 3,049,444 describes aself-wetting cellular synthetic plastic material which is impregnatedwith a wetting agent to improve its self-wetting proporties for use as afloral foam. According to that patent, the plastic material is foamedand is then provided with passages for holding ower stems. The wettingagent is applied from the passages to impregnato the interior portion ofthe foam body.

A search of the prior art since the development of my present inventionhas revealed that surface active sulionates have been included inphenolic materials during foaming as foam increasing agents in theproduction of cellular expanded thermoset resins having excellentbuoyancy properties by virtue of use of the surface active agents and aperoxide foaming catalyst. The production of such a material isdisclosed by Sterling in U.S. Pat. No. 2,629,698. Such foaming can alsobe conducted using a combination of azo compound and diisocyanate as afoaming catalyst; see Sterling in U.S. 2,608,536.

2 ADDITIONAL BACKGROUND ll'lPORMATION It has also been found that ureaformaldehyde resins l can be foamed to contain wetting agents by mixingthe wetting agent with the urea formaldehyde resin prior to foaming andby thereafter introducing foaming catalyst to foam the mass.

SUMMARY OF THB INVENTION This invention provides a foamed phenolicplastic having interconnected cells and containing anionic sulfonatewetting agent distributed through the plastic material of the mass andrendering the mass highly seltwetting when immersed in liquids.According to this invention, the foam can be produced by thoroughlymixing phenolic resin with a small amount of nnreacted anionic sulfonatewetting agent and treating the mixture with an inorganic mineral acid asthe foaming catalyst, without undue boiling or burning of the mixture,to produce the teamed phenolic product which still contains unreactedanionic sulfonate wetting agent. The anionic sulfonate wetting agent canbe isolated from the phenolic aud/or acid catalyst during foaming.

In a preferred method. the uonionic wetting agent and sulfonate wettingagent are added to two portions. Accordingly, one portion of thenonionic wetting agent is added followed immediately by a portion of thesulfonate wetting agent and the liquid is thoroughly mixed; then theremainder of the nonionic wetting agent is added followed immediately bythe remainder of the sulfonate wetting agent and thoroughly mixed,followed by addition and mixing of the inorganic mineral acid foamingcatalyst.

As a preferred feature of this invention, a mass of foam containingcarbon black pigment can be converted to a pleasant mossy green color bytreatment of the foam with gaseous ammonia. The ammonia also functionsto neutralize residual acid catalysts, although preferably it is usedonly to neutralize to a pH between 6 and `7 since this pH isparticularly adapdve to the preservation of tiowers.

While this invention is susceptible of embodiment in many differentforms, there is'shown in the th'awings and will be described herein indetail an embodiment of the invention with the understanding that theinvention is not considered to be limited by the embodiment illustratedand described.

BRIEF DESCRIPTION OF THB DRAWINGS FIG. 1 is a section of an embodimentof impregnated phenolic lioral foam according to a preferred form of theinvention; and

PIG. 2 is a diagrammatic showing enlarged from FIG. l, of a cell wallfor the purpose of showing how the wetting agent can be present withinthe phenolic foam structure.

DESCRIPTION 0F THE PREFERRED EMBODIMENTS Referring rst to the drawings,FIG, l illustrated a block 14 of oral foam material having passageway 16provided therein for supporting Alow'er stems as disclosed by my aboveidentied patent. Sulfonate wetting agent, as indicated by the stipplingat 1B, is uniformly distributed throughout the block 14 of foamedcellular material and occurs at the surface of the cell walls and mayoccur even within the cell walls. The cells of block 14 are of theinterconnected type providing ow passages from one cell to the next. Asseen in FIG. 2, it is believed that the cell walls 20 of the cells inthe foamed cellular structure 14 contain, interiorly and exteriorly,sulfonate wetting agent as indicated diagrammatically at 24 within orbetween protective material nared compounwhich'lnctionasagentsanrlwlrich-ar'eweltknowunothoseintlneortrlzey nature ofthest'rifonale isnnimportuutu longas itis sulfonateiselpeciallypradet-red.

Briey, thecailuiar massoi thisinveution ismade by mixingthesultonaterwith'a liquid phenolic resin and foaming with a mineralacid cater lyst..Where. lhesulonale islreuctive towardthe phenolicresin, it-hss-been'foundrthat mixing the resin with a nonionicwattinpagent prior to :addition of the.

sulIonate-isolates the snlfo'nate yin a manner blocking any reaction.Where the sulfonate is reactive toward'themineralacidmlyshithasbeenmmdthatadditionof nonionieaftereddition-oftheenlfonare undAprioa'toadditiondlhoacidcatalyatblockxthereaction.

'lhus;inapreerredormolthepresentinveotion. the.

phenolioreeinismixedwithobout 0.1 tof partahfywechtofznonionicwetnaaaenethenm topercentbywelsht. basedonphenollcresin, ofthe suliomte are added and aremixedinAnotiierOd to Sepansbyweigbt'ofnonionic wettingagent leihen added followed .by about l to 10parte by weighted mineral acid catalysLAlthough any ieusefulas catalyst.the preferred mineral acids `nre hydrochloric acid, sulfuric acid andphosphorio acid because of their availability. The resulting roamedproductie treated withsmmonium toneotralize muchfoithe'reaidualacid fromthe toamingprocess.

The roamedproduct is not only sell-'wetting with rospect towater..hutalso with respect to cranio liquids auch as kerosene, gasoline, andhydrocarbons. alcohols. ltete'nes,I andthersolvents, acids, alhallsandiiquied gases auch aaliquidomen. liquid nitrogen and the like..

Thusfthe foam-materialof this invention can ndapplitoninsuchsu'uctnresasairpianetueltankewiththe the fuel tankinterior and hoidingkeroseneorthelikeffromspilling incaseofanaccidentorimpact.

Asonetypicalexampleofthemamxfacuneolaselb'wettngfoamaccordingtothisinventiomasmallamnunt, about one part byweighhof -Dsxad [polymer-ized pots sium salts oialkyl nnphthalenesulfonic acids) wusrnixed for several minutes with 80 parts by welzhtrolBakelite phenolic resin BREL 2760 (resol phenolic resin). The Boxed wasadded aaa dispersing agent for dispersing materials to'belatenaddedandbleodedintothemix.'lheplesenceofthenaxadinthemixproducesamo uniform texturedfoamthroughoutafter expansion andaasuxesgood-densityoftheneclosesmnlloeilsinthe product.lpartsbyweinhtof'lweenNo. 40

expanded (polyoxyethylenesorbitan was added with blending for liveminuteeiu a mixer.

The functionptithe -Tween 401s to improve the resil.

ienceolthefoamandaidinproperexpamionotthe resin mix to a mood texmredformatter theacidcatalyst has beenzuddedvlhave found that for about liveminutesis adeqlmte to properlydispersethe Tween4 40 inthe-mixuuduly-longperiods od mixing appear to reduce the wetting'powerofrthe linished foamand too linie blending :ma :o pmdu a vennen, lange-celled,V

themixingtimecnnbeadjustedby indicare BenarZA-ltypeofsnlfonacedprodnctnreferredae a'wettingageotbecauseitlsextremeiystable enceotbothacidandalkalizccidietobefaddedus foaming catalyst andislnter to be -ueuu'alined with en: for han 1s :o so @wenn intermedioinclude somcpartlyaiedresininlhenxtoprowiebetteriomingtoadesireddensitybyslmviugdowmthecuringrewtionmd-therebyeliminatinglsrgepressnrecracksinthemaleriaLAfterthoronghlymixing. 8 partsbyweighiot hydrochloric acid wasadded tothe batch, followed bymixingornshort.periodoftime,e.g.,oneruinute.'lhemixutrewasthendumpedinamold.

'Ihefoamedproductrecoveredfrom-themoldwascut into slabs and placed in asteam-heated chamber and hestedtodriveoll'mostoftheacidcatnlystlheheatinthechamberwascutcdandsmallamountsofammoningaswereintrozhxoedintothechamberforaperlodof about one hour. The gasreadily penetratedthefoambecuuaeofthepartinlvamumcreatedbypre viens coolingof the foamfrom elevated andfthegaspenetrntesflmherintotheloumas uhefoamcoolsfurthenTheamountofanlnoniapenetratingthefoamisnotsucienttoreactwithorotherwisoderadctheenax 2A-1."lhe foam slabs when rst wtareblackincolorduetothepresenceofdrecarbonblack color material, but theammonia converts the black color toa 'very uniform green color 'which isan attractive color for menons: man

Then green `foanrprodvrced above waacut into blocks and provided'with =I:f ways 16. When placed in water, the blocksfabsorbed water andsankquickly. Flowers were then supported by their stemsintho L ye 16 andremained fresh for a considerable period of time.

As.V an example of the especially preferred method wherein I achievefast wetting time and maximum water absorption inthe foam producetheabove typicalen ample was repeated through the addition and oftheDaxadThenthe 1.8 perisbyweightothe'lween No. 40-waa added. `tollo'wedimmediately by 2.5 parte by weight of Benax 2A-1. The liquid wasthoroughly mixed for several minutes and another 1.8 parts by'weight ofTween No. 40 ma added. spin followed inmediately by another 2.5.parts byweightenax ZAPl. The mixing was continued-and lhenzthe aged DRL phenolicresin 2.759,A carbon black, additional fresh BRL phenolic resin 2159,isopropyl ether, additional Tweeno, und hydro chlorio acid camlystwereadded in as in thevtypical eurample.'I'hctoamproducthadamuchfnter-weingtime and higher water n propertiesthanthe one prepared above.

4A1I"parta anni percentages given herein are by weight unless otherwiseindicated.

I daim:

l. A- method ot producing a water absorbinghydrophilicphenollofoamofthetypeusefulforilomldisplays and the like.Iwhich method compriaeiihoroughly mixing suifonate wettingngent whilephysically isolating the y iight density foam; Within parameters.adjustment 75 resin from the sulfonste with an addition of a nonionicwetting agent to prevent reaction of the sulfonate with the resin andtreating the mixture of phenol-aldehyde resin and unreacted wettingagent with an inorganic mineral acid in the absence of material boilingand burning of the mixture until the mixture has been foamed andsolidified by curing and recovering the resulting foamed phenolicsolidified product containing anionic sulfonate wetting agent unreactedwith the phenol-aldehyde resin and mineral acid.

2. The method of claim 1 wherein said mineral acid is selected from theclass consisting of hydrochloric acid, sulfuric acid and phosphoricacid.

3. The method of claim 1 wherein said amount of sulfonate wetting agentis in the range of 11/5. to 3 percent by weight.

4. The method of claim 1 wherein said sulfonate wetting agent isldisodium 4-dodecylated oxydibenmene sulfonate.

5. The method of claim 1 wherein said sulfonate wetting agent is sodiumdioctyl sulfosuccinate.

6. The method of claim 1 wherein the addition of nonionic wetting agentis prior to adding and mixing the sulfonate wetting agent and in anamount sucient to physically separate the phenol-aldehyde resin from thelater added sulfonate wetting agent.

7. The method of claim 6 including the step of aldding additionalnonionic wetting agent after addition of the sulfonate wetting agent andbefore addition of the mineral acid in an amount physically separatingsaid sulfonate wetting agent from the later added mineral acid.

8. The method of claim 1 wherein said resin contains carbon blackpigment and including after foaming the step of treating the foam withammonia to convert the color to green.

9. The method of claim 1 wherein the addition of a rst portion of thenonionic wetting agent is prior to the addition and mixing of a portionof the sulfonate wetting agent and the addition of a second portion ofthe nonionic wetting agent is prior to the addition of the remainder ofthe sulfonate wetting agent.

10. The method of claim 9 wherein each addition of a portion of thenonionic wetting agent is followed immediately by addition of sulfonatewetting agent and thorough mixing.

11. The method of claim 10 wherein the two additions of nonionic wettingagent and sulfonate wetting agent are each approximately half of thetotal amounts of nonionic wetting agent and sulfonate wetting agent,respectively.

12. A method of producing green phenolic foam, which method comprisesfoaming and curing a mixture of pheno1-aldehyde resin, carbon black, andanionic sulfonate wetting agent while physically isolating the resinfrom the sulfonate with an addition of a nonionic wetting agent toprevent reaction of the sulfonate with the resin and treating theresulting solid foam with ammonia gas until green throughout.

13. A mass of water albsorptive cellular plastic comprising foamed andsolidified phenol-aldehyde resin having interconnected cells containingat the cell walls throughout the mass anionic sulfonate wetting agentphysically isolated by a nonionic wetting agent rendering the masshighly hydrophilic and quickly wet by aqueous media.

14. The mass of claim 13 wherein said anionic sulfonate wetting agent ispresent in an amount in the range of ll/z to 3 percent based on weightof said mass.

15. The mass of claim 13 wherein said sulfonate is reactive toward thephenolic resin and including a barrier layer of nonionic wetting agentisolating the sulfonate wetting agent from reaction with the phenolicplastic.

16. The mass of claim 15 wherein said barrier layer is nonionic wettingagent.

17. The mass of claim 13 including neutralized residual mineral acidwithin the foamed plastic.

18. The mass of claim 17 wherein said wetting agent is reactive towardsaid mineral acid and including barrier means isolating said wettingagent from said acid.

19. The mass of claim 18 wherein said barrier means is nonionic wettingagent.

20. The mass of claim 13 wherein said foamed phenolic plastic has astructure of unburned phenolic plastic cell walls defined by foamingwith mineral acid catalyst and wherein said sulfonate wetting agent issandwiched between barrier layers preventing reaction of the wettingagent with the phenolic plastic and acid.

21. The method of claim 1 wherein the addition of nonionic wetting agentis mixed with the phenol-aldehyde resin before said mixing step andincluding the step after said mixing step and before said treating stepof adding and mixing an additional amount of nonionic wetting agent forisolating the sulfonate between the additions of nonionic wetting agentto envelop the sulfonate wetting agent and render it non-reactive to thephenolaldehyde resin and the mineral acid.

22. lln a method of producing a phenolic foam wherein a liquidphenol-aldehyde resin is cured by foaming and solidifying using aninorganic mineral acid as the curing agent, the improvement by which thefoam is rendered water absorbing and useful for ilo-ral displays and thelike, which improvement comprises incorporating from about 0.1 to about5 percent by weight of an anionic sulfonate wetting agent in thephenol-aldehyde resin before curing and physically isolating thesulfonate wetting agent from the resin during the curing reactionwhereby the reaction proceeds without material burning of the foam.

References Cited UNITED STATES PATENTS 2,608,536 8/1952 Sterling 260-2.5F 2,629,698 2/1953 Sterling 260-2.5 F 2,653,139 9/1953 Sterling 26o- 2.5F 2,753,277 7/1956 Smithers 26o- 2.5 F 3,189,479 6/1965 Coppick et al260-2.5 F

JOHN C. BLEUTGE, Primary Examiner M. FOELAK, Assistant Examiner U.S. Cl.X.R. 26o-38, 59

